Austin police have discovered a 25-minute recording on a cellphone found with bombing suspect Mark Conditt and Austin Police Chief Brian Manley says he considers it a "confession."
Manley says at a news conference that Conditt talks on the recording in great detail about the differences among the bombs he built.
He says that the tape is "the outcry of a very challenged young man."
Officials say the 23-year-old Conditt blew himself up in his vehicle overnight as authorities closed in on him.
Teams working inside the Austin-area home of suspected bomber Conditt have ordered an evacuation of the surrounding six blocks after finding a "treasure trove" of evidence Wednesday, including homemade explosives.
Late Thursday afternoon, investigators wrapped up evidence gathering at Conditt's house in Pflugerville. The neighborhood was evacuated for a time on Wednesday when authorities announced they found homemade devices inside. Several windows in the house appeared to be recently boarded up. Investigators also towed a red pickup truck from the area before releasing the scene.
Officials have not said specifically what type of explosives were inside the 23-year-old man's Pflugerville home, which has been compared to a bomb-making factory, but did confirm explosives experts with the ATF and FBI were working to safely remove and dispose of the homemade devices and bomb-making material.
NBC News has learned that many of the components used in the devices, such as galvanized steel pipe, different types of shrapnel and a low explosive, were "fairly rudimentary" and were easily purchased at home goods and electronics stores in person or online. U.S. Rep. Mike McCaul (R-TX 10th District) told KXAN-TV in Austin that Conditt purchased some of the materials at a local Home Depot.
Officials said the consistency in components, such as an "exotic" battery from Asia, led investigators to believe the devices were all created by the same person. Additionally, officials said the devices were outfitted with a rudimentary switch or pin that used wadding between the switch to kept the circuit open. The circuit would close and the device would detonate when the package was opened or jostled and the wadding was moved out of place.
At about 10:30 a.m. Wednesday, investigators detained two of Conditt's roommates after SWAT officers surrounded his Pflugerville home on the 400 block of 2nd Street North. One was questioned and released. The other was released on Thursday afternoon.
Austin police, who declined to release the names of Conditt's roommates because they are not under arrest, said they are still investigating whether Conditt worked alone. They also said they don't know his motive.
Also Wednesday morning, and only blocks from the suspect's home, agents with the FBI and ATF entered the home of Conditt's parents.
Officials said late Wednesday morning the suspect's family has been very cooperative with law enforcement and that they don't believe the family had any knowledge of the suspect's alleged activity.
Conditt's immediate family plans to release a statement through the Austin police sometime Wednesday afternoon. Conditt's extended family in Denver released the following statement to KUSA-TV:
"We are devastated and broken at the news that our family member could be involved in such an awful way. We had no idea of the darkness that Mark must have been in. Our family is a normal family in every way. We love, we pray, and we try to inspire and serve others. Right now our prayers are for the families who lost loved ones, for those impacted in any way, and for the soul of our Mark. We are grieving and in shock. Please respect our privacy as we deal with this terrible, terrible knowledge and try to support each other at this time.
Conditt apparently killed himself early Wednesday morning when, surrounded by police, he detonated a bomb inside his car, bringing a dramatic end to a weekslong siege of the Texas capital where two people were killed and four injured in a series of explosions.
Austin Police Chief Brian Manley said Wednesday morning authorities zeroed in on Conditt over the last 24 to 36 hours and tracked him to a hotel on Interstate 35 in the north Austin suburb of Round Rock, north of Pflugerville.
NBC 5 obtained an arrest warrant and criminal complaint showing federal agents were looking for Conditt Tuesday evening, had secured a warrant for his arrest and planned to charge him with unlawful possession and transfer of a destructive device prior to his apparent suicide along I-35.
WOAI-TV in San Antonio confirmed Wednesday afternoon that Conditt used the alias Kelly Killmore when shipping his package bombs. Police, meanwhile, advise citizens to remain vigilant as there may be other packages that are still out there since they don't know where the suspect was in the 24 hours prior to his apparent suicide.
The family of Draylen Mason, who was killed earlier this month by one of the package bombs, released the following statement upon hearing the news of the suspect's death.
We want to thank the law enforcement officials who have worked diligently on this case. We have been humbled by the overwhelming support of the community and of those who loved Draylen as we did. Our hearts also go out to the families who have been impacted by these senseless crimes and we pray for them as well. We are a family of faith and we know that with God all things are possible. The most recent chain of events have brought some sense of closure that our beloved has received justice and we are prayerful that we can now start to move forward with our lives. While we never imagined that he would not be with us at this time, we are comforted to know that Draylen has received the reward of eternal life that can only be granted by Our Heavenly Father through Jesus Christ. We await that day when we can rejoice in Our Lord and see Draylen once again.